1.简介
AChartEngine(简称ACE)是Google的一个开源图表库(for Android)。它功能强大,支持散点图、折线
。关于里面类的具体使用,请下载响应的文档说明(主页上有)。
2.开发步骤
1)在工程中新建一个文件夹比如lib,用于存放ACE
Libraries,把achartegine-0.5.0.jar包复制到lib里面。然后把这个jar的路径添加到项目的Build Path中。
2)修改AndroidManifest.xml
主要是加入一个<activity>:
< activity android:name = "org.achartengine.GraphicalActivity"
/>
3)绘制柱状图
public class main extends ListActivity {
private static final int SERIES_NR = 2;
/** Called when the activity is first created. */
private ArrayList<Map<String,String>> maps = new
ArrayList<Map<String,String>>();
@Override
public void onCreate(Bundle savedInstanceState) {
super .onCreate(savedInstanceState);
// setContentView(R.layout.main);
// 加入 ListItem “ 调度查询 ”
HashMap<String,String> map= new
HashMap<String,String>();
map.put( "name" , " 柱状图 " );
map.put( "desc" , " 显示柱状图 " );
maps .add(map);
// 构建 listView 的适配器
SimpleAdapter adapter= new SimpleAdapter( this
, maps ,
android.R.layout. simple_list_item_2 , // SDK
库中提供的一个包含两个 TextView 的 layout
new String[]{ "name" , "desc" }, // maps 中的两个
key
new int []{android.R.id. text1 ,android.R.id.
text2 } // 两个 TextView 的 id
);
this .setListAdapter(adapter);
}
// ListItem 监听器方法
protected void onListItemClick(ListView l, View v, int
position, long id) {
super .onListItemClick(l, v, position, id);
XYMultipleSeriesRenderer renderer =
getBarDemoRenderer();
Intent intent = ChartFactory.getBarChartIntent
( this , getBarDemoDataset(), renderer, Type. DEFAULT );
startActivity(intent);
}
private XYMultipleSeriesDataset getBarDemoDataset() {
XYMultipleSeriesDataset dataset = new
XYMultipleSeriesDataset();
final int nr = 10;
Random r = new Random();
for ( int i = 0; i < SERIES_NR ; i++) {
CategorySeries series = new
CategorySeries( "Demo series " + (i + 1));
for ( int k = 0; k < nr; k++) {
series.add(100 + r.nextInt() %
100);
}
dataset.addSeries(series.toXYSeries());
}
return dataset;
}
public XYMultipleSeriesRenderer getBarDemoRenderer() {
XYMultipleSeriesRenderer renderer = new
XYMultipleSeriesRenderer();
SimpleSeriesRenderer r = new
SimpleSeriesRenderer();
r.setColor(Color. BLUE );
renderer.addSeriesRenderer(r);
r = new SimpleSeriesRenderer();
r.setColor(Color. GREEN );
renderer.addSeriesRenderer(r);
setChartSettings(renderer);
return renderer;
}
private void
setChartSettings(XYMultipleSeriesRenderer renderer) {
renderer.setChartTitle( "Chart demo" );
renderer.setXTitle( "x values" );
renderer.setYTitle( "y values" );
renderer.setXAxisMin(0.5);
renderer.setXAxisMax(10.5);
renderer.setYAxisMin(0);
renderer.setYAxisMax(210);
}
}
代码解析:在 onListItemClick
方法中,当用户点击了“显示图表”之后,构造一个intent对象,然后用startActivity发送消息到前面
AndroidManifest.xml申明的那个activity( 即 GraphicalActivity
)。于是图表就显示出来了。关键是intent的构造方法 ChartFactory.getBarChartIntent。
ChartFactory提供了许多有用的工厂方法,如果你需要生成一个折线图,可以用它的 getLineChartIntent 方法。
getBarChartIntent 方法有点复杂,需要我们准备很多参数传入。其中一个是 XYMultipleSeriesDataset
类型的对象,用于提供图表需要表示的数据集,这里我们用 getBarDemoDataset 来得到它。另外一个是
XYMultipleSeriesRenderer 类型的对象,用于提供图表展现时的一些样式,这里我们用 getBarDemoRenderer
方法来得到它。
getLineChartIntent 方法很无聊,使用了一些随机数来作为图表数据。注意柱状图是支持多系列的,这里生成了两个系列的数据。
getBarDemoRenderer 方法构建了一个 XYMultipleSeriesRenderer 用来设置2个系列各自的颜色,然后调用
setChartSettings 方法设置了下坐标轴样式。
4)绘制曲线
import java.util.ArrayList;
import java.util.List;
import org.achartengine.ChartFactory;
import org.achartengine.chart.PointStyle;
import org.achartengine.model.XYMultipleSeriesDataset;
import org.achartengine.model.XYSeries;
import org.achartengine.renderer.XYMultipleSeriesRenderer;
import org.achartengine.renderer.XYSeriesRenderer;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
public class chartDemo extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
String[] titles = new String[] { "First",
"Second"};
List x = new ArrayList();
List y = new ArrayList();
x.add(new double[] { 1, 3, 5, 7, 9, 11} );
x.add(new double[] { 0, 2, 4, 6, 8, 10} );
y.add(new double[] { 3, 14, 5, 30, 20, 25});
y.add(new double[] { 18, 9, 21, 15, 10, 6});
XYMultipleSeriesDataset dataset =
buildDataset(titles, x, y);
int[] colors = new int[] { Color.BLUE,
Color.GREEN};
PointStyle[] styles = new PointStyle[] {
PointStyle.CIRCLE, PointStyle.DIAMOND};
XYMultipleSeriesRenderer renderer =
buildRenderer(colors, styles, true);
setChartSettings(renderer, "Line Chart Demo",
"X", "Y", -1, 12, 0, 35 , Color.WHITE, Color.WHITE);
View chart =
ChartFactory.getLineChartView(this, dataset, renderer);
setContentView(chart);
}
protected XYMultipleSeriesDataset buildDataset(String[]
titles,
List xValues,
List yValues)
{
XYMultipleSeriesDataset dataset = new
XYMultipleSeriesDataset();
int length = titles.length;
//有几条线
for (int i = 0; i < length; i++)
{
XYSeries series = new
XYSeries(titles[i]); //根据每条线的名称创建
double[] xV =
xValues.get(i);
//获取第i条线的数据
double[] yV =
yValues.get(i);
int seriesLength = xV.length;
//有几个点
for (int k = 0; k <
seriesLength; k++) //每条线里有几个点
{
series.add(xV[k],
yV[k]);
}
dataset.addSeries(series);
}
return dataset;
}
protected XYMultipleSeriesRenderer buildRenderer(int[]
colors, PointStyle[] styles, boolean fill)
{
XYMultipleSeriesRenderer renderer = new
XYMultipleSeriesRenderer();
int length = colors.length;
for (int i = 0; i < length; i++)
{
XYSeriesRenderer r = new
XYSeriesRenderer();
r.setColor(colors[i]);
r.setPointStyle(styles[i]);
r.setFillPoints(fill);
renderer.addSeriesRenderer(r);
}
return renderer;
}
protected void setChartSettings(XYMultipleSeriesRenderer
renderer, String title,
String xTitle,String yTitle, double
xMin,
double xMax, double yMin, double yMax,
int axesColor,int labelsColor)
{
renderer.setChartTitle(title);
renderer.setXTitle(xTitle);
renderer.setYTitle(yTitle);
renderer.setXAxisMin(xMin);
renderer.setXAxisMax(xMax);
renderer.setYAxisMin(yMin);
renderer.setYAxisMax(yMax);
renderer.setAxesColor(axesColor);
renderer.setLabelsColor(labelsColor);
}
}